exists and is an alternate of . Since this is regarding statistics I assume you mean lower case sigma (Ï) which, in statistics, is the symbol used for standard deviation, and Ï2 is known as the variance.
The Acceptable Quality Limit, commonly referred to as AQL, is a method widely used to measure a production order sample to find whether or not the entire product order has met the client's specifications. The customer then has the data to make an informed decision to accept or reject the lot.
The minimum limit you can report it called Limit of Quantification (LOQ) is the level above which quantitative results may be obtained with a specified degree of confidence. LOQ must be higher than or equal detection limit, generally two to five times of calculated MDL.